[Progressive myoclonic epilepsy: anatomo - clinical study of a sporadic case with a marked cerebellar symptomatology (author's transl)].

A case of progressive myoclonic epilepsy (P.M.E.) is described. The clinical picture consisted of epileptic seizures, myoclonus and slight mental deterioration associated with a severe progressive cerebellar syndrome. The disease had a course of almost 20 years. Histological studies of the C.N.S. showed severe loss of Purkinje cells, sligth regressive changes in both dentate and olivary nuclei, nerve cells atrophy of anterior horn motoneurons, degeneration of Goll's and Burdach's spino-olivary and anterior spino-cerebellar tracts. Features of cellular lipidosis and/or neuronal amiloid inclusions were not seen. The case was therefore classified in the group of degenerative P.M.E. Its peculiar pathologic aspects consisted of slight but diffuse brain stem regressive changes associated with systemic degeneration involving the spino-cerebellar pathways. The clinical features of our patient emphasize the problem of differential diagnosis between. P.M.E. and D.C.M. thought of by French authors to be an autonomous entity both clinically )severe cerebellar syndrome, intentional myoclonus, absence or late appearance of epilepsy, slight or absent mental deterioration) and anatomically (primary atrophy of the dentate system). However there are many cases, similar to the one reported, which have a clinical course suggesting a diagnosis of D.C.M., but which differ neuropathologically from Hunt's syndrome because of the absence of primary atrophy of the dentate system. These borderline cases give supporting evidence to the concept of continuity between classical P.M.E. and D.C.M., as well as to the authors' opinion that 1unt's syndrome must be classified as a varient of degenerative P.M.E.